Individuals diagnosed with some chronic illnesses are often prescribed medicines that must be injected at regular intervals. In general, it is necessary for patients to inject themselves with the medication. One of the most common self-injected medications is insulin which is prescribed in the treatment of diabetes.
In the following description, for the sake of convenience, the monitoring device of the invention and injection devices incorporating the monitoring device will be described in relation to diabetes patients and insulin injection pens used by those patients. However, as will be appreciated by those skilled in the art, the problems faced by insulin users are increasingly common to many medical conditions, such that the monitoring devices and injection devices (such as pens of the invention incorporating the monitoring devices) have wide application in the dosing of a wide range of medications for various medical conditions. Accordingly, the invention should not be construed as being limited to the automatic monitoring of insulin dosages or the treatment of diabetes.
Those diagnosed with diabetes know that much of their long-term health depends on good diabetes management. Tracking one's diabetes and managing glucose and insulin levels is essential in order to avoid serious complications such as increased morbidity and mortality, cardiovascular, cerebrovascular and peripheral vascular disease.
Type 1 diabetes is diagnosed when the body fails to produce sufficient insulin with the result that a periodic insulin injection is required to control glucose levels in the body. A major risk with insulin injection is accidental or inadvertent insulin overdose. An insulin overdose results in very low blood sugar levels (hypoglycemia) giving rise to symptoms such as headache, irregular heartbeat, increased heart rate or pulse, sweating, tremor, nausea, increased hunger, disorientation and anxiety. Failure to rapidly diagnose and treat hypoglycemia can lead to coma.
Diabetes patients generally employ injection devices known as insulin pens and it is imperative for insulin pen users to keep accurate track of the type and amount of insulin they are injecting.
Individual insulin products are numerous, but insulin may be divided into four major types. Short-acting insulin is a soluble insulin that acts quickly (30-60 minutes) and lasts for between 6 and 8 hours while some types may be faster-acting and shorter-lasting. Intermediate-acting insulin or lsophane insulin acts at a slightly slower rate (1-2 hours) and lasts for between 10 and 14 hours while long-acting insulin (e.g. insulin detemir, insulin glargine, protamine zinc insulin and insulin zinc suspension) act slowly (1-2 hours) and last for up to 24 hours. Mixtures of insulin such as mixed short and intermediate-acting insulin in accordance with an individual's needs can also be used.
As indicated above, insulin pen users can suffer long-term health consequences if they do not adhere accurately and carefully to a dosage schedule.
However, insulin pens and similar devices are nor smart devices. No method exists for automatically monitoring the intake of insulin using insulin pens—typically manual paper records must be maintained by the user or smart handheld devices such as mobile phones or tablets can be used to again manually store insulin dosages and patterns.
More particularly, it is not currently possible to accurately and effectively automatically record and monitor insulin injections administered via insulin pens. Moreover, manual recording by end users whether on paper or smart handheld devices does not allow for individual patient insulin dosages to be recommended (to the patient) and reported (to a medical professional) for analysis. In short, known insulin pens frequently fail to protect users from under or over dosages.
Attempts have been made to develop monitoring devices for injection devices that record dosages and transmit the dosage data to remote devices. For example, it is known to use monitoring devices fitted with cameras and Optical Character Recognition (OCR) units to simply photograph and record the dosage displayed on the dosage display of the injection pens. However, such monitoring devices can be difficult to position over the dosage display for the camera to photograph the dosage, while even if correctly positioned the display can be difficult for the camera to read depending on its format. This is particularly the case where non-Roman numerals are displayed. Moreover, OCR requires such a high processing power that it may not be possible to process the data on a small monitoring device and external processing power may be required giving rise to additional complexity and manufacturing cost. In addition, the camera used must provide extremely high levels of clarity for the OCR software giving rise to significant camera hardware costs that can be prohibitive while the associated optics are also complex and necessarily expensive.